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View Full Version : strange slowdown (possible resource exhaustion?)



andras
03-29-2006, 03:35 PM
In my app, I cache chunks of renderable data (texture + vertex buffer pairs) in a pool. I can set the size of this pool, and if I let the number of chunks go above a certain number, then the app slows down drastically, with the driver eating up most of the frame time.

The threshold where this slowdown happens is different on each computer, but just to give an idea it's around a thousand. Is having more than a thousand textures and vertex buffers considered a lot? Does anyone have experience using this many resources?

I don't think it's a memory issue, as I use small, compressed textures (approx 30MB total), and small VBOs (approx 6MB total).

Any ideas? I might be totally on the wrong track here, but it seems like that decreasing the pool size makes the problem go away..

I'm running GF6x00 with 81.98 drivers.

andras
03-29-2006, 04:06 PM
Ok, it's all my fault, sorry..
At one point in time, I've changed the textures from compressed to uncompressed (just for testing purposes), and I forgot to set it back (and accidentally even submitted it :mad: ). So instead of ~30MB of textures, I was using ~240MB of textures and running out of vram..

Jan
03-29-2006, 04:24 PM
How do you achive an 8:1 compression ratio?
I mean, hardware can do up to 4:1 compression, so i assume you simply downscale your textures, or did i miss something?

Jan.

andras
03-29-2006, 09:06 PM
DXT1 is 4 bits/pixel while RGB is 32 (internally it's stored as RGBA on most video cards).

Jan
03-30-2006, 12:49 AM
Oh, i always had in mind DXTC could only compress up to 4:1. No wonder my app is so much faster with texture compression enabled :-)